Int US 65 Folder Collection
After playing the video, you can click or select the word to look it up in the dictionary.
Report Subtitle Errors
It's AumSum Time.
Can you guess the title of my next video?
Hurry up.
Write your guess in the comments section below.
Are you afraid of heights?
Do you think it is because of vertigo?
Vertigo is not necessarily fear of heights.
In medical terms, vertigo refers to a false
sensation of movement due to which we feel dizzy.

The most common type of vertigo is Benign Paroxysmal Positional Vertigo or BPPV.
It is caused when our inner ear which helps us maintain balance by detecting motion and position of our body.
Doesn't function properly.
Normally, when we move our head, the cilia
and calcium crystals in our inner ear move.

Thus sending signals to the brain about our movement.
However, sometimes some crystals dislodge and move into the fluid filled semicircular canals.
Now, when we move our head, the crystals move along with the fluid.
However, even after our head movement has stopped, the crystals keep moving in the canals.
Thus sending wrong signals to the brain that our head is still moving.
Due to this wrong information, the person gets a false sensation of movement which makes him feel dizzy.
Thus causing vertigo.
How do fireflies glow?
Using a magic wand.
Fireflies glow because they produce light
by a biochemical reaction.

In the lower abdomen of fireflies, there is a chemical called luciferin and an enzyme called luciferase.
When oxygen enters into their lower abdomen through tracheal tubes.
It basically reacts with luciferin in the presence of luciferase.
This reaction produces light.
This production and emission of light by a
living organism is called bioluminescence.

Bioluminescence is a cold light.
This means the light produced generates very less heat.
Thus, preventing the firefly's abdomen from getting overheated.
Yes dude.
It is not hot.
However, one more interesting fact is that not only adult fireflies but also their eggs and larvae are bioluminescent.
They look so stunning.
Why honey doesn't spoil?
Coz honey is actually a magical potion.
Honey doesn't spoil mainly because of osmosis.
Osmosis is the movement of water from a region of higher water concentration.
Through a semi-permeable membrane to a region of lower water concentration.
Now, the water content in honey is far less than the water content in organisms like bacteria and fungi.
Hence, when such organisms try to enter honey.
The water from their bodies moves out into the honey due to osmosis.
As a result, they die and thus, the honey
doesn't spoil.

In addition to this, some bees produce antibiotics within their bodies to protect themselves against certain bacteria.
However, when bees make honey, some of these antibiotics get added to the honey.
These antibiotics also prevent the growth
of bacteria, thus preventing the honey from spoiling.

What is fracking?
A dance form.
Deep inside the earth, there is a layer of
shale rocks.

These rocks contain fossil fuels like oil
and gas in their pores.

To extract these fuels, a technique called
fracking or hydraulic fracturing is used.

In fracking, a vertical well is drilled into
the layer of shale rocks.

Then, the drill is turned by 90 degrees and
drilling continues horizontally.

When the targeted distance is reached, the
fracking well is encased.

Then, a perforating gun is inserted in the well.
When the perforating gun reaches the required distance, the rocks are perforated.
Then, the perforating gun is removed and a
fracking fluid is pumped in the well.

This fluid builds pressure in the perforations, creating cracks in the rocks, thus releasing the fossil fuels.
These fuels and the fracking fluid are then
drawn to the surface.

Topic: Rust.
Why is oxalic acid used to remove rust stains?
You have a beautiful antique lamp.
But look.
It has a rust stain on it.
Don't clean the rust stain with water.
Instead, use this oxalic acid.
Oxalic Acid.
You just don't want my lamp to be nice and
shiny, do you?

No, I am helping you.
Why don't you listen?
Because I know that you are making a fool
out of me.

Go ahead.
Oh no.
I had told you.
Now will you use the oxalic acid?
The stain disappeared.
Do you know how this happened?
Let me tell you.
Rust is hydrated iron oxide.
It is formed when iron reacts with oxygen
and water.

Rust is insoluble in water.
Hence, it is quite difficult to remove rust

So, how does oxalic acid remove the stain?
Does it have some supernatural powers?
Absolutely not.
Oxalic acid reacts with rust to form iron
oxalate complex ion.

Iron oxalate complex ion is soluble in water.
Thus, it can easily be washed away, helping us remove the rust stain.
    You must  Log in  to get the function.
Tip: Click on the article or the word in the subtitle to get translation quickly!


Are you Afraid of Heights? | Vertigo | #aumsum

65 Folder Collection
AumSum published on April 15, 2019
More Recommended Videos
  1. 1. Search word

    Select word on the caption to look it up in the dictionary!

  2. 2. Repeat single sentence

    Repeat the same sentence to enhance listening ability

  3. 3. Shortcut


  4. 4. Close caption

    Close the English caption

  5. 5. Embed

    Embed the video to your blog

  6. 6. Unfold

    Hide right panel

  1. Listening Quiz

    Listening Quiz!

  1. Click to open your notebook

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔